In the use of a continuous track assembly, it is desirable to controllably position the wheels of the track assembly relative one to the other to properly maintain tension of the track about the wheels.
For example, a continuous track assembly is used on a work vehicle to provide increased traction. The track assembly generally includes wheels about which a track is positioned. It is desirable that the track conform to uneven terrain during operation of the vehicle and not penetrate the terrain surface. This provides maximum tractive effort and does not seriously disturb ground conditions.
Heretofore, track tensioning has been commonly maintained or adjusted by providing horizontal movement of one wheel relative to another wheel as is common on track-type tractors. Such track tensioning devices are shown, for example, in U.S. Pat. Nos. 4,149,757 which issued to T. C. Meisel, Jr. on Apr. 17, 1979, and U.S. Pat. No. 2,719,062 which issued to B. F. Arps on Sept. 27, 1955. Such track assemblies result in a generally rigid structure which resists the tendency of the track assembly components to adapt to the working environment. In vehicles operating over rough terrain, such as log skidders, the result can be a tractive effort or disturbance of the ground which is unacceptable for the particular working environment. Also, the operator typically must be more attentive to travel areas of the vehicle, which can limit its versatility.
In order to maximize adaptation of the vehicle to its environment to solve such problems, it can be desirable to allow wide pivotal movement of one or more of the wheels about which the track is positioned. However, it may therefore be necessary to permit pivotal movement of a wheel driven by a power source on the vehicle. More conventional track assemblies, such as in the above-described patents, typically do not provide this possibility. Also, the track assemblies disclosed in U.S. Pat. No. 4,087,135 which issued on May 2, 1978, to D. H. Unruh, U.S. Pat. No. 2,496,136 which issued on Jan. 31, 1950, to R. W. Smith, and British Pat. No. 611,543 issued to R. F. Skelton and published on Nov. 1, 1948, do not lend themselves to such pivotal action.
The present invention is directed to overcoming one or more of the problems as set forth above.